if (method.getParameterTypes().length == 1
&& method.getParameterTypes()[0].equals(cls)) {
XmlElementDecl elementDecl = method.getAnnotation(XmlElementDecl.class);
if (null != elementDecl) {
QName elementType = new QName(elementDecl.namespace(), elementDecl.name());
registry.registerDeserializer(parentType, elementType, helper);
registry.registerSerializer(parentType, elementType, helper);
registry.mapExtensionTypes(parentType, elementType, cls);
registry.createExtension(parentType, elementType);
}